1. Field of the Invention
This invention relates to an electrical terminal that includes a hollow conductive terminal body containing an opening for receiving a conductor, a spring being provided within a chamber defined within the terminal body for biasing the conductor toward electrical engagement with a given wall of the chamber. The spring includes a leg having an operating tab portion that extends externally of the terminal via a slot contained in said given wall, thereby to permit the spring leg to be displaced to a retracted position for the insertion or withdrawal of the conductor from the terminal chamber.
2. Brief Description of the Prior Art
Resilient electrical terminals are well known in the patented prior art, as illustrated, for example, by the prior German patent No. DE 19614977, and the U.S. patents to Wielsch, et al., U.S. Pat. No. 6,270,383 and Despang U.S. Pat. No. 6,350,162, among others. In such terminals, it is known to provide a resilient member that biases a bare conductor into engagement with the conductive terminal wall. In the German patent, a projecting portion of the spring affords means for displacing the legs of the spring toward an open condition for the insertion and removal of the conductor relative to the terminal.
The present invention was developed to provide a spring terminal that can be made at reasonable cost with a particularly simple design that can be connected and disconnected in a simpler manner than the various types of currently available typical spring terminals.
Accordingly, a primary object of the present invention is to provide a resilient electrical terminal including a hollow conductive terminal body containing an opening communicating with a chamber within the terminal body, and a U-shaped spring mounted in said chamber, said spring having an outwardly biased contact leg for biasing an electrical conductor that is introduced into the chamber via said opening toward electrical engagement with a given wall of the chamber, said contact leg having an operating tab that extends outwardly from the terminal body via a slot contained in the chamber wall. The terminal body and the spring are each formed by bending a strip of metal stock material. Upon operation of the operating tab, the contact leg is displaced from a normal clamping position toward a released position, thereby to permit the conductor to be inserted into, or withdrawn from, the chamber.
Since the resilient terminal assembly requires only a few simple parts each formed from sheet metal, it is easily and inexpensively produced. By simple manipulation of the operating tab externally or the terminal, the spring contact leg may be displaced to the released position for insertion and withdrawal of the conductor from the terminal chamber. Furthermore, a rigid conductor may be merely inserted directly into the terminal chamber by force fit and without any operation of the operating tab.
According to a further object of the invention, a protective synthetic plastic insulating housing may be mounted upon the terminal assembly following its soldering connection with the printed circuit board. Locking foot means may be provided for releasably connecting the protective housing with the terminal assembly and/or the printed circuit board.
According to another embodiment of the invention, two or more springs may be provided within a single terminal body for connecting a plurality of conductors with the terminal body. Each spring includes a leg having an operating tab portion that extends outwardly via an associated slot, respectively. Thus, selective operation of the operating lugs permits insertion and removal of the various conductors, respectively.
According to a further modification, the two legs of a single U-shaped spring may be utilized to bias a pair of conductors toward engagement with opposed walls of the terminal chamber, respectively, each spring leg being provided with an operating tab portion.
Another object of the invention is to provide a terminal block that contains one or more of the terminal assemblies, said terminal block containing first openings that receive the operating tool that engages the operating tab on a spring leg, and second openings through which the conductors are inserted within and removed from the terminal chambers, respectively.
The present invention permits the terminal block assemblies to be soldered to a printed circuit board, and to be subsequently enclosed in a protective housing.